The present invention relates to a time division speech path apparatus of a digital switching system.
In a conventional time division speech path apparatus of a digital switching system, when a plurality of highways having different phases are used as input highways, time division switching is performed in the following manner. A buffer memory is arranged for each input highway. The frame phases of the overall highways are synchronized by performing frame synchronization in such a manner that write operations are performed in accordance with the phases of the input highways, and read operations are performed in accordance with the specific system phase of the speech path. Data from the highways having synchronized frame phases are multiplexed and written in a speech path memory, and data is read out from the speech path memory in accordance with contents read out from a speech path control memory.
In the above-described conventional time division speech path apparatus, since the buffer memories are arranged for the respective input highways, an increase in delay time cannot be avoided. In addition, with an increase in speed of a highway, the required capacity of a buffer memory is increased, resulting in an increase in hardware amount of the system.